1. Field of the Invention
The present invention relates to a light-transmitting conductive film, a display device that uses the light-transmitting conductive film, an electronic device that uses the light-transmitting conductive film, and a manufacturing method of the light-transmitting conductive film. In particular, the present invention relates to a light-transmitting conductive film that is formed using conductive oxynitride including zinc and aluminum, and a manufacturing method of the light-transmitting conductive film.
2. Description of the Related Art
In recent years, liquid crystal display devices, light-emitting display devices, and electrophoretic display devices which are typified by flat panel displays have been actively developed. Most of them have a structure in which a displayed image or display light is seen through a transparent electrode in which transparent conductive oxide is used. As an example of the transparent conductive oxide, an indium oxide-tin oxide compound (In2O3—SnO2, abbreviated to ITO) film formed using a target obtained by adding tin oxide to indium oxide and performing sintering can be typically given. Having a lower resistivity than transparent conductive oxides using other materials and high transparency in a visible light region, ITO is often used as a transparent electrode in flat panel displays and the like.
However, indium which is a main material of ITO is a rare metal and very expensive and may cause the increase in cost of flat panel displays and the like. Further, indium resources are in danger of depletion, and discovery of an alternative material is desired from the standpoint of environmental protection.
As an alternative transparent conductive oxide to ITO, transparent conductive oxide using zinc oxide (ZnO) can be given. Although transparency and conductivity of ZnO are inferior to those of ITO, ZnO is a very inexpensive material as compared to ITO. For example, the cost of a target formed by sintering ZnO is approximately two thirds to half of the cost of a target formed by sintering ITO. As a method to improve the conductivity of ZnO, a method for forming transparent conductive oxide including a slight amount of aluminum functioning as a donor in ZnO is known (Patent Document 1).